Performance Investigation of Glazing Systems in Combination with Internal Solar Shading
Authors
Hedegaard, Jakob ; Iversen, Tore Dahl
Term
4. term
Publication year
2015
Submitted on
2015-06-10
Pages
96
Abstract
I Danmark vælger rådgivende ingeniører i stigende grad indvendig, dynamisk solafskærmning (fx justerbare persienner) frem for udvendig, statisk afskærmning. De vigtigste årsager er, at udvendige systemer er meget følsomme over for vejret og ofte kolliderer med facadens arkitektur. Når et vindue med indvendig afskærmning simuleres i bygningssimuleringsprogrammet BSim, bliver bygningens solvarmetilskud dog ofte overvurderet. Det sker, fordi afskærmningskoefficienten behandles som en konstant, selv om den i praksis ændrer sig med solens indfaldsvinkel. Afskærmningskoefficienten angiver, hvor meget solenergi der slipper gennem vinduet og afskærmningen. Projektet har til formål at bestemme et korrektionstal for afskærmningskoefficienten, så BSim-resultaterne bliver mere præcise. Da det ikke vides, hvordan forskellige vindues- og afskærmningstyper påvirker størrelsen af overvurderingen, undersøges to vinduestyper kombineret med flere typer indvendig afskærmning. Målet er at vurdere, om én generel korrektion kan bruges på tværs af kombinationer, eller om der kræves specifikke korrektioner for hver vindues- og afskærmningskombination.
In Denmark, consulting engineers increasingly prefer internal, dynamic solar shading (for example, adjustable blinds) over external, static shading. The main reasons are that external systems are sensitive to bad weather and can conflict with the building’s façade design. However, when a window with internal shading is modeled in the widely used building simulation program BSim, the building’s solar heat gain is often overestimated. This happens because the shading coefficient is treated as a constant, even though it actually varies with the sun’s angle of incidence. The shading coefficient indicates how much solar energy passes through the window and its shading. This project aims to estimate a correction factor for the shading coefficient to improve the accuracy of BSim results. Because it is not known how different window and shading types affect the amount of overestimation, the study examines two window types in combination with several shading types. The goal is to determine whether one general correction is sufficient for all combinations, or whether each window–shading combination needs its own specific correction.
[This abstract was generated with the help of AI]
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